Some computer networks, such as High-Performance Computing (HPC) networks and data centers, comprise multiple nodes that communicate using the Infiniband™ protocol. Infiniband is described, for example, in “Infiniband™ Architecture Specification—Volume 1,” release 1.2.1, November, 2007, which is incorporated herein by reference. Chapter 5 of this specification defines data packet formats for Infiniband networks.